The present invention relates generally to firearms, and more particularly to a bolt head and bolt carrier assembly for a semiautomatic weapon which prevents a locking ring from freely vibrating to thereby prevent the locking ring from compressing so far that the locking ring enters an annular space within the bolt carrier.
Various bolt head and bolt carrier assemblies are known in the firearm art. For example, a bolt assembly for a semiautomatic weapon is described in U.S. Pat. No. 6,101,919 issued to Murello which claims priority from German Patent DE 197 13 988. In this example, a bolt assembly is constructed from a rotatable bolt head and a bolt carrier. When the bolt assembly is unlocked the bolt head rotates and returns into a longitudinal groove of the weapon housing. During the return into the longitudinal groove, the bolt head is not guided but instead it is held at a fixed distance from the bolt carrier by means of a locking ring.
The locking ring is an elastic sleeve made of spring sheet divided longitudinally by a longitudinal slit. In the loaded, or compressed state, (i.e., when the locking ring is compressed radially), the longitudinal slit is compressed in the peripheral direction and the locking ring has a circular cross section. In the unloaded, or uncompressed state, (i.e., when the locking ring is expanded radially), the longitudinal slit is opened and the locking ring has the cross section of roughly an opened oval.
The bolt head has a rim of locking pegs on its front end, which are distributed in the peripheral direction, similarly to the US M16 automatic rifle. In the unlocked position the rim of locking pegs has a spacing relative to the bolt carrier. The locking ring is in the unloaded state and surrounds the rearward facing shaft of the bolt head. The locking ring is supported against the rear end of the rim and the front end surface of the bolt carrier and, therefore, prevents further penetration of the shaft into the bolt carrier. An annular space surrounding the shaft is formed between the bolt head shaft and the bolt carrier.
In the unlocked position, the rear end of the locking ring sits on the front end surface of the bolt carrier, but cannot penetrate into the annular space because the unloaded locking ring has an oval, or non-circular cross section which is unable to penetrate the annular space. Alternatively, the cross section of the unloaded locking ring may be circular. However, when this locking ring is unloaded, the outside diameter of the locking ring is then greater than the outside diameter of the annular space.
When the bolt assembly is closed, (i.e., moved into the locked position), the bolt head and locking pegs pass between protrusions that are mounted on the weapon housing. The locking ring then contacts a beveled rear edge of the protrusions and is compressed radially into the loaded state. The locking ring is, thereby, tightly compressed around the shaft of the bolt head with its rear end precisely opposite the entrance of the annular space of the bolt carrier. The shaft with the locking ring tightly enclosing it can penetrate into the annular space either partially, or in its entirety.
Upon unlocking of the bolt assembly, the bolt carrier moves rearward relative to the bolt head and releases the front section of the bolt head shaft and the locking ring. After release, the locking ring springs back to its unloaded position and ensures that the spacing between the bolt head and bolt carrier is maintained during any back-and-forth movement until the bolt is relocked.
This known bolt assembly has proven to be reliable in experiments and by its utilization, it has become possible to simplify the design of the bolt housing since the bolt housing no longer has to guide the bolt head. In rare instances, however, the locking ring does not prevent the shaft from penetrating the annular space even when the locking ring is in the unloaded, expanded state.
A bolt assembly is provided for use in a firearm having a barrel and a locking element formed at the proximal end of the barrel. The bolt assembly comprises a bolt carrier and a bolt head. It further includes a connecting device operatively coupling the bolt carrier and the bolt head. Mounted on the connecting device is an elastic sleeve having an expanded state, and a compressed state. The elastic sleeve contacts both the bolt carrier and the bolt head in the expanded state, to thereby substantially prevent relative longitudinal movement between the bolt head and the bolt carrier. Compression of the elastic sleeve toward the compressed state permits relative longitudinal movement between the bolt head and the bolt carrier. Means are provided for damping vibrations of the elastic sleeve.